**8. Summary and Outlook**

(Cr,Al)N and (Al,Cr)N coatings are amongst the main PVD coatings in commercial applications and offer a high degree of freedom to tailor the coating structure and properties by controlling the chemical composition and tuning the deposition process parameters. The coating architectures which can be achieved range from simple monolayers to heterogenous multilayers combining AlCr-based layers with other material systems. The present status and current trends can be summarised briefly as follows:


**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Acknowledgments:** The authors are thankful for the input received and the fruitful discussions enjoyed with all of our Oerlikon Balzers colleagues, including Jürgen Ramm, Arnd Müller, Ali Khatibi, Siegfried Krassnitzer, Denis Kurapov, and Hossein Najafi (Oerlikon Metco). In addition, the authors also wish to thank Christian Mitterer (Montanuniversität Leoben, Austria), Paul Mayrhofer (TU Vienna, Christian Doppler Laboratories, Austria) and Michael Stüber (KIT, Karlsruhe, Germany) for their constructive input in the form of discussions.

**Conflicts of Interest:** The authors declare no conflict of interest.
